You should definitely take advantage of the office hours! I found them to be helpful, but I also found that I had to drive the discussions.
I got the most value out of them when I showed up with an agenda - a list of the things I'd done in Marketo that I wanted reviewed so we could tweak them if there was a better way, a list of questions on videos, and things I wanted to do that I just wanted a more experience set of eyes watching over my shoulder as I did them (ie - sending out my first campaign).
Hope that helps, and welcome to Marketo! 🙂